Hard tissue anchors and delivery devices

ABSTRACT

The present invention provides devices, systems and methods for anchoring medical devices to hard tissues, such as bones or bony structures, particularly vertebrae. By anchoring these medical devices directly to the surrounding hard tissue, the devices are anchored closer to the source of treatment. This provides additional stability and reduces migration of the device at the treatment site. Also, by attaching to hard tissue rather than soft tissue, a stronger attachment is often able to be made.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims priority of provisional patent application No.60/873,549 (Attorney Docket No. 10088-708.101), filed on Dec. 6, 2006,which is incorporated herein by reference for all purposes.

STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSOREDRESEARCH AND DEVELOPMENT

NOT APPLICABLE

REFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAMLISTING APPENDIX SUBMITTED ON A COMPACT DISK

NOT APPLICABLE

BACKGROUND OF THE INVENTION

A variety of implantable medical devices are used to treat portions ofthe anatomy which reside near bones or bony structures within the bodyof a patient. Such devices are typically anchored in place by suturingportions of the device to surrounding soft tissue. Often the deviceincludes suture holes designed specifically for this purpose atpredetermined locations along the device. Thus, the device may only besutured at these locations, limiting the areas and types of tissueavailable for suturing thereto. Often, the location is far from thetreatment site. Such distance and instability of anchoring tissue cancontribute to lead migration and pull-out.

For example, conventional spinal cord stimulators (SCS) are positionedalong the spinal column to treat pain. A conventional SCS systemcomprises an implantable lead and an implantable power source orimplantable pulse pulse generator IPG. Using fluoroscopy, the lead isimplanted into the epidural space of the spinal column and positionedagainst the dura layer of the spinal cord. The lead extends from thespinal column to the IPG which is remotely implanted. Typically, thelead is sutured to soft tissue remote from the point of entry into theepidural space. And, lead migration and pull-out are common problemsassociated with SCS.

Therefore, it is desired to provide a more stable anchoring system forimplantable devices, such as leads. Such an anchoring system shouldprovide anchoring at desired locations rather than merely at locationsalong the device which are predesigned for anchoring. Such anchoringshould also assist in resisting migration and pull-out. At least some ofthese objectives will be met by the present invention.

BRIEF SUMMARY OF THE INVENTION

The present invention provides devices, systems and methods foranchoring medical devices to hard tissues, such as bones or bonystructures, particularly vertebrae. A variety of medical devices areused to treat portions of the anatomy which reside near bones or bonystructures within the body of a patient. The devices and systems of thepresent invention are suitable for use with many of such medical devicesand specialized devices used for particular treatments. By anchoringthese directly to the surrounding hard tissue, the devices are anchoredcloser to the source of treatment. This provides additional stabilityand reduces migration of the device at the treatment site. Also, byattaching to hard tissue rather than soft tissue, a stronger attachmentis often able to be made.

In a first aspect of the present invention, a hard tissue anchor isprovided for securing an element to a hard tissue. In some embodiments,the hard tissue comprises a penetrating end shaped for penetrating thehard tissue, and a head having an aperture, wherein the aperture isconfigured to receive the element therethrough and wherein the head isconfigured to secure the element within the aperture. Typically, theelement comprises a lead, however catheters or other devices may beused.

In some embodiments, the head includes a channel connected to theaperture, wherein the channel is configured allow passage of the elementfrom outside of the head to the aperture. In some instances, the head isadjustable to close the channel, such as by deformation of the head.Optionally, deformation of the head may secure the element within theaperture. In some embodiments, the head further comprises a grommetdisposed within the aperture. The grommet may assist in holding theelement within the aperture.

In some embodiments, the penetrating end has a tapered, conical,notched, barbed or serrated shape. In such instances, the hard tissueanchor is considered a tack and is pressed into the hard tissue. Inother embodiments, the penetrating end has a shank with a helicalthread. In these instances, the hard tissue anchor is considered a screwand is rotated into the hard tissue.

In a second aspect of the present invention, a method is provided foranchoring an element to a hard tissue in a body: In some embodiments,the method comprises advancing a hard tissue anchor toward the hardtissue, wherein the anchor has a penetrating end and a head having anaperture, positioning the element within the aperture, and applyingpressure to the head so as to drive the penetrating end at leastpartially into the hard tissue.

In some embodiments, applying pressure comprises applying pressure tothe head so as to secure the element within the aperture. Optionally,applying pressure comprises deforming the head so as to secure theelement within the aperture due to friction.

In some instances, the method further comprises implanting the elementin the body. Such implanting may occur before the positioning step ofpositioning the element within the aperture. This allows the hard tissueanchors to be utilized with existing implanted systems.

In still further embodiments, the anchor includes a channel connected tothe aperture and the method further comprises passing a portion of theelement through the channel to the aperture. Optionally, applyingpressure comprises deforming the head so as to at least partially closethe channel.

To deliver a hard tissue anchor of the present invention, such methodsmay include mounting the head of the anchor on a distal end of anapplicator. In some situations, advancing the hard tissue anchor towardthe hard tissue comprises advancing the distal end of the applicatorthrough a percutaneous access opening. In such instances, the applicatorhas a low profile suitable for such percutaneous delivery.

In some embodiments, applying pressure to the head comprises applyingpressure to the applicator. Optionally, applying pressure to theapplicator may comprise deforming the head by force of the applicator soas to secure the element within the aperture due to friction.

In a third aspect of the present invention, an applicator is providedfor delivering a hard tissue anchor. In some embodiments, the applicatorcomprises an elongate body having a proximal end and a distal end,wherein the distal end is configured to receive a head of the hardtissue anchor, and a handle attached to the proximal end of the elongatebody so that force applied to the handle is translatable to the head ofthe hard tissue anchor. Optionally, the elongate body may be shaped forpassage through a percutaneous access opening.

In some embodiments, the applicator further comprises a release buttonfor releasing the hard tissue anchor from the distal end of the elongatebody. The distal end may include a recess for receiving the head, fromwhich the hard tissue anchor is releasable.

When the hard tissue anchor comprises a bone tack, the force typicallycomprises longitudinal force which is translatable to a downward forceon the head of the hard tissue anchor. When the hard tissue anchorcomprises a bone screw, the force typically comprises rotational forcewhich is translatable to rotation of the head of the hard tissue anchor.In such instances, the distal end may comprise a rotatable memberjoinable with the head, wherein the rotation force rotates the rotatablemember.

Other objects and advantages of the present invention will becomeapparent from the detailed description to follow, together with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a hard tissue anchor of the present invention usedwith a conventional SCS system.

FIG. 2 illustrates a hard tissue anchor of the present invention usedwith a lead which is implanted near a DRG to provide selectivestimulation thereto.

FIG. 3 illustrates an embodiment of a bone tack of the presentinvention.

FIG. 4 illustrates an embodiment of a bone tack having an elementthreaded through its head prior to implantation of the element.

FIG. 5 illustrates a side view of a tack having a channel along the topof the head.

FIG. 6 illustrates a top view of such the tack of FIG. 5.

FIG. 7 illustrates passing an element through a channel in the head of abone tack.

FIG. 8 illustrates a lead surrounded by a silicone tube positionedwithin arms of the head of a bone tack.

FIGS. 9A-9B illustrate an embodiment of a bone tack having a grommet.

FIG. 10 illustrates a tack having a grommet wherein the channel of thegrommet has been closed by crimping of the head.

FIGS. 11A, 11B, 11C, 11D illustrate front, side, top and bottom views,respectively, of one embodiment of a bone tack of the present invention.

FIG. 12 illustrates an applicator for delivery of a bone tack to aportion of a hard tissue.

FIG. 13 illustrates a distal end of the applicator having a recess forreceiving a head of a bone tack.

FIG. 14 illustrates a bone tack securely fixed to an applicator duringinsertion via friction fit with a grommet.

FIGS. 15A, 15B, 15C, 15D, 15E illustrates various views elongate body ofan applicator having an insert positionable within its distal end.

FIG. 16 illustrates an embodiment of a bone screw of the presentinvention.

FIGS. 17A, 17B, 17C, 17D, 17E illustrate various view of an embodimentof a bone screw.

FIGS. 18A-18B illustrate an applicator for delivery of a bone screw to aportion of a hard tissue.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides devices, systems and methods foranchoring medical devices to hard tissues, such as bones or bonystructures, particularly vertebrae. A variety of medical devices areused to treat portions of the anatomy which reside near bones or bonystructures within the body of a patient. For example, spinal cordstimulators (SCS) are positioned along the spinal column to treat pain.FIG. 1 illustrates a conventional SCS system comprising an implantablelead 100 and an implantable power source or implantable pulse pulsegenerator IPG. Using fluoroscopy, the lead 100 is implanted into theepidural space E of the spinal column S and positioned against the duralayer of the spinal cord. The lead 100 is implanted either through theskin via an epidural needle (for percutaneous leads) or directly andsurgically through a mini laminotomy operation (for paddle leads). Ineither case, the leads 100 extend from the spinal column S to the IPGwhich is remotely implanted. Typically, the leads 100 are sutured tosoft tissue remote from the point of entry into the epidural space E.Such suturing is often insufficient to adequately the implanted lead100, thus leading to migration or pull-out. FIG. 1 illustrates a hardtissue anchor 600 of the present invention used in conjunction with theconventional SCS system to anchor the implantable lead 100. As shown,the anchor 600 can be used to attach the lead 100 a hard tissue, such asa vertebrae V near the point of entry to the epidural space E. Thisprovides more secure anchoring by fixing to a harder tissue and reducesthe distance between the distal portion of the lead and the site ofanchoring. This assists in reducing migration and pull-out of the lead100.

In addition, the devices, systems and methods of the present inventionmay be used to anchor other types of medical devices, in particularvarious other types of leads used to selectively stimulate the spinalanatomy, particularly the dorsal root or dorsal root ganglion (DRG).FIG. 2 illustrates a lead 150 which is implanted near a DRG to provideselective stimulation thereto. Examples of such leads are provided inU.S. patent application Ser. No. 11/952,049, filed Dec. 6, 2007,entitled “Grouped Leads For Spinal Stimulation”, (Attorney Docket No.10088-706.201/Client Ref No. SM-00610US) and U.S. patent applicationSer. No. 11/952,053, filed Dec. 6, 2007, entitled “Grouped Leads ForPosterior Access Of Directed Spinal Stimulation” (Attorney Docket No.10088-707.201/Client Ref No. SM-00710US), both incorporated herein byreference. As shown, a hard tissue anchor 600 of the present inventionmay be used to anchor the lead 150 to a portion of the vertebrae V whichis near the DRG. This anchors the lead 150 close to the stimulation siteand reduces migration or pull-out of the lead 150.

The hard tissue anchors 600 of the present invention include bone tacksand bone screws. FIG. 3 illustrates an embodiment of a bone tack 601 ofthe present invention. The bone tack 601 can be used to anchor anelement, such as a lead or catheter, to a bone or bony structure, suchas near to a site of an intended application. In this embodiment, thebone tack 601 has a head 602 and a penetrating end 604 opposite the head602. The penetrating end 604 may have a tapered, conical, notched,barbed, serrated or otherwise shaped end which is suitable forpenetrating bone B, as shown. The head 602 includes an aperture 607through which the element 152 can be threaded prior to implantation ofthe element 152, as illustrated in FIG. 4. The bone tack 601 is advancedalong the element 152 to the desired anchoring position. Force is thenapplied to the head 602 to advance the penetrating end 604 into the boneB, thereby fixing the element 152 to the bone B at that location. Thismay be achieved during the implantation procedure of the element 150.

Other embodiments of the bone tack 601 are particularly suited foranchoring the element 150 at an anchoring location when it is lessdesirable to pre-load the anchor on the element 150. This may be thecase when the element 150 is already implanted or it is not possible toadvance an anchor over the element 150, such as from one of the ends ofthe element 150 to the anchoring location. In some of these embodiments,the head 602 of the bone tack 601 includes a channel 608 which connectsto the aperture 607. FIG. 5 illustrates a side view of an embodiment ofa tack 601 having such a channel 608 along the top of the head 602, andFIG. 6 illustrates a top view of such a tack 601. The tack 601 can beslipped over the element 150 through the channel 608 in the head 602 sothat the element 150 passes through the aperture 607, as illustrated inFIG. 7. Thus, the tack 601 can be positioned at any location along theelement 150. The channel 608 can then be closed by deformation of thehead 602. Further deformation of the head 602 crimps the head 602 ontothe element 150 resisting relative motion.

FIG. 8 illustrates a lead 610 surrounded by a silicone tube 612positioned within arms 614 of the head 602 of a bone tack 601. Deformingor crimping of the head 602 (at least one arm 614) holds the siliconetube 612 in relation to the head 602 and further crimping holds the lead610 in relation to the silicone tube 612. Thus, various degrees ofdeformation may be used to provide differing desired results.

In some embodiments, the tack 601 includes a grommet 606, as illustratedin FIGS. 9A-9B. The grommet 606 includes a channel which is alignablewith the channel 608 of the head 602. Thus, an element 150 may be passedthrough the channel 608 of the head 602 and the aligned channel of thegrommet 606. The grommet 606 assists in applying friction to the element150 and protects the element 150 from possible damage. Deformation orcrimping of the head 602 applies further friction to the element 150,such as fixing the element 150 within the grommet 606. FIG. 10illustrates a tack 601 having a grommet 606 wherein the channel of thegrommet 606 has been closed by crimping of the head 602. Thisillustrates the reduction in size of the aperture an therefore increasedfriction against the element 150.

FIGS. 11A, 11B, 11C, 11D provide front, side, top and bottom views,respectively, of one embodiment of a bone tack 601 of the presentinvention. In this embodiment, the tack 601 has a 0.060 inch diameterhead 602 with a 0.040 inch diameter aperture 607. Further, the head 602has a 0.008 inch channel 608. This embodiment also includes apenetrating end 604 having serrations which taper from a first serrationhaving a width of 0.045 inches to a second serration having a width of0.035 inches to a point. The penetrating end 604 has a length of 0.105inches from the center of the aperture 607. Thus, the bone tacks 601 ofthe present invention typically have a small size to allow positioningin confined or hard to reach areas of the anatomy. It may be appreciatedthat such dimensions are exemplary and are not intended to limit thescope of the present invention.

The head 602 and a penetrating end 604 are typically formed from thesame material and may comprise any biocompatible and/or bioresorbablematerial including but not limited to cobalt chromium, cobalt chromiumalloys, titanium, titanium alloys, stainless steel, resorbable PGA orPLA, and PEEK.

The grommet 606 may be comprised of any soft biocompatible and/orbioresorbable material including but not limited to silicone orpolyurethane. The grommet 606 could be an assembly or molded onto thetack 606.

The bone tacks 601 of the present invention are driven into a portion ofbone B by mechanical force, such as tapping or pressing. Referring toFIG. 12, an applicator 620 is provided for delivery of the bone tack 601to a portion of a bone B. The applicator 620 is designed so that thetack 601 can be delivered through a percutaneous access opening andpositioned at an anchoring location via fluoroscopy or other imagingtechniques. Typically, the applicator 620 comprises an elongate body 300with a low profile to assist in accessing a variety of target locationswithin the body. The elongate body 300 has a proximal end 302 and adistal end 304, wherein the distal end 304 is configured to receive thehard tissue anchor 600. In most embodiments, the applicator 620 alsoincludes a handle 306 attached to the proximal end 302 of the elongatebody 300.

FIG. 13 illustrates an embodiment of a distal end 304 of the applicator620 having a recess 624 for receiving a head 602 of a bone tack 601. Insome embodiments, the bone tack 601 is securely fixed to the applicator620 during insertion via friction fit with the grommet 606, asillustrated in FIG. 14. The tack 601 is penetrated and anchored into thebone B via the penetrating end 604, by application of downward orlongitudinal force on the tack 601 by the applicator 620. Thus, forceapplied to the handle 306 is translatable to the head 602 of the hardtissue anchor 600 and drives the anchor 600 into the hard tissue. Insome embodiments, such force also then crimps the head 602 onto anelement passing through the aperture 607. The tack 601 can then bereleased from the applicator 620, such as with the use of a releasebutton 626. The tack 601 is then left behind with the element passingtherethrough.

In some embodiments, the distal end 304 is comprised of an insert thatis inserted into the elongate body 300. FIGS. 15A-15E illustrate variousviews of an elongate body 300 having an insert 301. Typically the insert301 is formed or machined so that together the insert 301 and theelongate body 300 desirably receive the bone tack 601. FIG. 15Aillustrates a side view of an insert 301 having a recess 624 forreceiving a bone tack 601. Here the recess 624 has a depth of 0.050inches and a width of 0.060 inches. FIG. 15B illustrates an embodimentof an elongate body 300 having a length of 0.105 inches and a width of0.28 inches. FIG. 15C illustrates a bottom view of an insert 301 showingrecess 624. The insert 301 is inserted into a slot 303 in the elongatebody 300, illustrated in FIG. 15D. In this embodiment, the slot 303 hasa depth of 0.105 inches and a width of 0.028 inches. FIG. 15Eillustrates a side view of the elongate body 300 having a notch 305.When a bone tack 601 is inserted into the distal end 304, as illustratedin FIG. 14, the aperture 607 of the bone tack 601 is exposed to allow anelement to pass therethrough. Referring back to FIG. 15E, in thisembodiment, the notch 305 has a width of 0.033 inches. It may beappreciated that the dimensions noted herein are examples.

Example methods of installing a bone tack 601 of the present inventionare described herein. In one embodiment, a tack 601 of the presentinvention is mounted in an applicator 620 as described above. Anelement, such as a lead 610, is threaded through the aperture 607 of thetack 601 while the tack 601 is held in the applicator 620. The tack 601is inserted into a percutaneous access site, locating the target bone orbony structure via fluoroscopy or other imaging method. The lead 610 ispositioned as desired for its intended therapeutic purpose. The bonetack 601 is then tapped into place so that the penetrating end 604sufficiently penetrates the target bone or bony structure and the headcrimps the lead. The applicator 620 is then removed.

Thus, the bone tacks 601 of the present invention can be used to securevarious devices without the use of sutures. Further, such securing oranchoring can be achieved in percutaneous procedures without the needfor a large surgical exposure. And, such securing and anchoring iseasily achievable without excessive manipulation, particularly with theuse of the deformable head which secures the lead during insertion ofthe tack into bone. Likewise, this action is assisted by the use of theapplicator which is able to hold the tack and deform the head whileinserting the tack into the bone.

FIG. 16 illustrates an embodiment of a bone screw 650 of the presentinvention. The bone screw 650 can also be used to anchor an element,such as a lead or catheter, to a bone or bony structure near to a siteof an intended application. The bone screw 650 has a head 652 and apenetrating end 654 opposite the head 652. Typically, the penetratingend 654 has a tapered shank with a helical thread which is suitable forturning or twisting into bone. In some embodiments, the thread isparticularly suitable for penetrating cortical bone. Cortical threadforms are generally finer pitched (more threads per inch) and shallowerthan thread forms designed to penetrate cancellous bone. In someembodiments, the helical thread has a pitch of 0.020-0.200 inches, moreparticularly 0.029 inches. Typically, the penetrating end 654 isself-tapping and does not require the use of a bone tap to implant thebone screw 650 into the hard tissue. In some embodiments, thepenetrating end 654 has an acute nose angle to assist in self-tapping,such as a 60 degree nose angle. In some embodiments, a wedge is added tofurther assist in self-tapping, such as a 30 degree wedge.

The head 602 includes an aperture 657 through which the element 152 canbe threaded prior to implantation of the element 152 in a manner similarto the bone tack 601 of FIG. 4. Or, the screw 650 can be slipped over aportion of the element 152 through a channel 658 in the head 652 whichconnects to the aperture 657 in a manner similar to the bone tack 601 ofFIG. 7. Optionally, the bone screw 650 may include a grommet havingsimilar features to the grommet 606 described previously in relation tobone tacks 601.

FIGS. 17A-17E provide various views of one embodiment of a bone screw650 of the present invention. FIG. 17A illustrates a perspective view ofa bone screw 650 similar to the bone screw of FIG. 16. However in thisembodiment, the penetrating end 654 has a thread which is more suitablefor penetrating cancellous bone. FIG. 17B illustrates a side view of thebone screw 650 of FIG. 17A. In this embodiment, the head 652 has adiameter of approximately 0.14 inches and an aperture 657 having adiameter of approximately 0.06 inches. Likewise, the head 652 has a 0.03inch channel 658. The penetrating end 654 has a length of 0.38 inchesfrom the center of the aperture 657 and a diameter of approximately 0.10inches (as illustrated in the top view of FIG. 17E). Referring to FIG.17C and its cross-section shown in FIG. 17D, the penetrating end 654 hasa shank with a helical thread with a pitch of 0.075 inches. Thus, thebone screws 650 of the present invention typically have a small size toallow positioning in confined or hard to reach areas of the anatomy. Itmay be appreciated that such dimensions are exemplary and are notintended to limit the scope of the present invention.

The head 652 and a penetrating end 654 of the bone screws 650 aretypically formed from the same material and may comprise anybiocompatible and/or bioresorbable material including but not limited tocobalt chromium, cobalt chromium alloys, titanium, titanium alloys,stainless steel, resorbable PGA or PLA, and PEEK.

The bone screws 650 of the present invention are driven into a hardtissue, such as a portion of bone B, by rotational force. Referring toFIGS. 18A-18B an applicator 660 is provided for delivery of the bonescrew 650 to a portion of a bone B. The applicator 660 is designedsimilarly to the bone tack applicator 620 in that it has a low profileso that the screw 650 can be delivered through a percutaneous accessopening and positioned at an anchoring location via fluoroscopy or otherimaging techniques. Again, the applicator 660 typically comprises anelongate body 670 having a proximal end 672 and a distal end 662,wherein the distal end 662 is configured to receive the hard tissueanchor 600. In most embodiments, the applicator 660 also includes ahandle attached to the proximal end 672 of the elongate body 670.

FIG. 18A illustrates an embodiment of a distal end 662 of the applicator660 having a recess 664 for receiving a head 652 of a bone screw 650.The applicator 660 includes a rotatable member 661 which is joinablewith the bone screw 650. FIG. 18B illustrates a bone screw 650 securelyfixed to the rotatable member 661 via friction, such as with a grommet.The screw 650 is penetrated and anchored into the bone B via rotation ofthe penetrating end 604 by rotating the member 661. When it is desiredto deform or crimp the head 652, force may be applied to the handle andtranslated to the head 652 which crimps the head 652 onto an elementpassing through the aperture 657. The screw 650 can then be releasedfrom the applicator 660, such as with the use of a release button.

One challenge of a twisting or screw-type penetration is that theorientation of the aperture 657 depends on how the screw 650 is screwedin. Also, placing the lead into the aperture 657 after delivery may bedifficult due to its orientation. These challenges are overcome by thebone screws 650 of the present invention. The bone screw 650 may bescrewed in place at a desired location first and then the element, suchas a lead, is loaded through the channel 658 in the head 652. The leadis then advanced to a desired position for the therapeutic applicationand secured in place by crimping of the head 652.

Although the foregoing invention has been described in some detail byway of illustration and example, for purposes of clarity ofunderstanding, it will be obvious that various alternatives,modifications and equivalents may be used and the above descriptionshould not be taken as limiting in scope of the invention.

1. A hard tissue anchor for securing an element to a hard tissuecomprising: a penetrating end shaped for penetrating the hard tissue;and a head having an aperture, wherein the aperture is configured toreceive the element therethrough and wherein the head is configured tosecure the element within the aperture.
 2. A hard tissue anchor as inclaim 1, wherein the element comprises a lead.
 3. A hard tissue anchoras in claim 1, wherein the head includes a channel connected to theaperture, wherein the channel is configured allow passage of the elementfrom outside of the head to the aperture.
 4. A hard tissue anchor as inclaim 3, wherein the head is adjustable to close the channel.
 5. A hardtissue anchor as in claim 4, wherein the head is adjustable bydeformation of the head.
 6. A hard tissue anchor as in claim 5, whereindeformation of the head secures the element within the aperture.
 7. Ahard tissue anchor as in claim 1, wherein the head further comprises agrommet disposed within the aperture.
 8. A hard tissue anchor as inclaim 1, wherein the penetrating end has a tapered, conical, notched,barbed or serrated shape.
 9. A hard tissue anchor as in claim 1, whereinthe penetrating end has a shank with a helical thread.
 10. A method foranchoring an element to a hard tissue in a body, the method comprising:advancing a hard tissue anchor toward the hard tissue, wherein theanchor has a penetrating end and a head having an aperture; positioningthe element within the aperture; and applying pressure to the head so asto drive the penetrating end at least partially into the hard tissue.11. A method as in claim 10, wherein applying pressure comprisesapplying pressure to the head so as to secure the element within theaperture.
 12. A method as in claim 11, wherein applying pressurecomprises deforming the head so as to secure the element within theaperture due to friction.
 13. A method as in claim 10, furthercomprising implanting the element in the body.
 14. A method as in claim13, wherein the positioning step occurs after the implanting step.
 15. Amethod as in claim 10, wherein the anchor includes a channel connectedto the aperture and further comprising passing a portion of the elementthrough the channel to the aperture.
 16. A method as in claim 15,wherein applying pressure comprises deforming the head so as to at leastpartially close the channel.
 17. A method as in claim 10, furthercomprising mounting the head of the anchor on a distal end of anapplicator.
 18. A method as in claim 17, wherein advancing the hardtissue anchor toward the hard tissue comprises advancing the distal endof the applicator through a percutaneous access opening.
 19. A method asin claim 17, wherein applying pressure to the head comprises applyingpressure to the applicator.
 20. A method as in claim 17, whereinapplying pressure to the applicator comprises deforming the head byforce of the applicator so as to secure the element within the aperturedue to friction.
 21. An applicator for delivering a hard tissue anchor,the applicator comprising: an elongate body having a proximal end and adistal end, wherein the distal end is configured to receive a head ofthe hard tissue anchor; and a handle attached to the proximal end of theelongate body so that force applied to the handle is translatable to thehead of the hard tissue anchor.
 22. An applicator as in claim 21,wherein the elongate body is shaped for passage through a percutaneousaccess opening.
 23. An applicator as in claim 21, further comprising arelease button for releasing the hard tissue anchor from the distal endof the elongate body.
 24. An applicator as in claim 21, wherein thedistal end includes a recess for receiving the head.
 25. An applicatoras in claim 21, wherein the force comprises longitudinal force which istranslatable to a downward force on the head of the hard tissue anchor.26. A hard tissue anchor as in claim 21, wherein force comprisesrotational force which is translatable to rotation of the head of thehard tissue anchor.
 27. A hard tissue anchor as in claim 21, wherein thedistal end comprises a rotatable member joinable with the head, whereinthe rotation force rotates the rotatable member.